Although releasable pedal bindings for bicycles have been known for many years, as evidenced, for example, by 1895 U.S. Pat. No. 550,409 to Hanson, such devices are now increasingly demanded by competitors as well as by bicycle enthusiasts in general. Discriminating users have imposed exacting specifications, such as (1) engagement and disengagement by foot movement alone; (2) insurance against accidental release; (3) adjustable release force; (4) compactness to ensure against any compromise of cornering clearance, to ensure that the ball of the foot is comfortably close to the pedal axis, and to ensure light weight; (5) secure connection free of slack with not discomfort imposed.
Several devices have attempt to satisfy these criteria. The mechanism shown in 1987 U.S. Pat. No. 4,686,867 to Bernard and Mercier and the KEYWIN binding manufactured by Keywin Sports Limited of New Zealand are both widely used. Yet they suffer certain disadvantages. For example, the KEYWIN binding utilizes a leaf spring as the operative element of the latch. This leaf spring in incapable of adjustment, and for some, difficult to operate. Entry into the KEYWIN binding is cumbersome, and not well assisted by the mechanism. The Bernard/Mercier mechanism utilizes a weight biased binding that tilts upwardly for easy automatic entry, and in this report is superior to the KEYWIN binding. But the Bernard/Mercier mechanism utilizes a latching claw that pivots rearwardly about an axis essentially parallel to the pedal axis. For latching, a transverse cam surface along the back of the cleat is provided that engages a transverse cam surface of the claw. Upon exertion of heavy downward step-in pressure, the claw yields rearwardly and then snaps over the cleat. Release occurs by motion in a different direction, namely angular foot movement about a vertical axis. But the same strong spring forces must be overcome to effect release. The cam surfaces to achieve release necessarily have only slight slope in order to obtain the necessary force multiplication. As a consequence, sidewise slack is difficult to eliminate. The coupling is or becomes less than rigid.
One of the objects of the present invention is to provide a pedal binding that meets the essential criteria above set forth, which is free of the foregoing disadvantages.
Along the path of travel, a cyclist may encounter certain traffic or other conditions that suggest the possibility, but not the certainty, that a stop may be required. It is an object of the present invention to provide a pedal binding that allows the cyclist to prepare for a stop by releasing the latch without actually uncoupling the binding parts. The cyclist then has the option to effect quick unrestrained desengagement at the last possible moment, maintaining control and power in the interim. If it is determined that a stop is not needed, the binding is easily reconnected by a simple angular movement of the foot.
Neither the KEYWIN nor the Bernard/Mercier structure is capable of such operation. Anticipation is not possible; either the device is coupled or released. There is no middle ground. Thus, when the latch is released, power can no longer be effectively applied to the pedal. Needless release and reconnect operations may recur with loss of control and power; or the cyclist may unduly delay a decision to release.